Cold brew tea: ratio and steep times

By exactee · Updated 2026-10-13

For cold brew tea, use about 8–10 g of loose-leaf tea per litre of cold water and steep it in the fridge: green tea 4–8 hours, white tea and oolong 6–10 hours, black tea 8–12 hours. Strain, keep refrigerated and drink within about two days. Herbal and fruit infusions are better brewed hot for food-safety reasons.

Why cold brew tastes different

Cold water extracts tea slowly and selectively. Caffeine and catechins, the compounds behind bitterness and astringency, dissolve much less readily in cold water than in hot. Many aromatic and sweet compounds still come through. The result is a smooth, naturally sweet, low-bitterness tea that almost can’t be over-steeped. It is the easiest way to make delicate green tea taste good.

Cold brew ratio and times

That is roughly 2–2.5 g for a 250 ml glass. Prefer stronger? Add leaf rather than time. Time matters less in cold water than in hot, but very long steeps (over a day) can still turn grassy or flat.

Step by step

1. Weigh the leaf into a clean jar or bottle. Loose leaf works better than bags.
2. Add cold, filtered water. Room-temperature water is fine to start, but the jar goes straight into the fridge.
3. Close and refrigerate for the time in the table.
4. Strain completely. Keep the tea in the fridge and drink it within about two days.

How long does green tea take in cold water?

Green tea is the fastest: 4–6 hours in the fridge is a good range for most, and Japanese steamed teas can taste ready after about 3 hours. Overnight (8 hours) is also fine and a little stronger.

Is cold brew tea safe?

Tea leaves are a dried agricultural product and are not sterile. With hot brewing, boiling water takes care of most microbes. With cold brewing, it doesn’t. Sensible habits keep the risk low: clean jars, fridge rather than counter, strain after steeping, and drink within a day or two.

For herbal and fruit infusions the German Federal Institute for Risk Assessment (BfR) advises preparing them with boiling water and letting them steep for at least five minutes, because dried herbs and fruit pieces can occasionally carry bacteria such as salmonella. Products specifically sold for cold infusion are an exception, as they are made for that use; follow the label. For classic tea from the tea plant, the cautious approach above is what most tea makers recommend.

Cold brew vs. iced tea

Cold brew steeps in cold water for hours. Iced tea is brewed hot and then chilled or poured over ice, which is quicker and gives a brisker, more tannic taste. For the classic American version, see iced tea ratio and sweet tea.

Does cold brew have less caffeine?

Usually somewhat less than the same leaf brewed hot for a few minutes, because caffeine dissolves more slowly in cold water. Very long steeps narrow the gap. It still contains caffeine, so treat it like regular tea.

Tips

• Use loose leaf: whole leaves unfurl slowly and give a cleaner taste.
• Try “ice brewing”: put leaves under ice cubes and let them melt. It’s slow but very sweet, especially with sencha.
• Add fruit or herbs after straining, not during, for a fresher taste.
• Scale any amount with the calculator using roughly a third of the hot-brew leaf per ml, then adjust.